<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			.content {
			    float: left;
			    width: 100%;
			}
			.main {
			    height: 200px;
			    margin-left: 110px;
			    margin-right: 220px;
			    background: green;
			}
			.main::after {
			    content: '';
			    display: block;
			    font-size:0;
			    height: 0;
			    zoom: 1;
			    clear: both;
			}
			.left {
			    float:left;
			    height: 200px;
			    width: 100px;
			    margin-left: -100%;
			    background: red;
			}
			.right {
			    float: right;
			    height: 200px;
			    width: 200px;
			    margin-left: -200px;
			    background: blue;
			}
		</style>
	</head>
	<body>
		<div class="content">
		    <div class="main"></div>
		</div>
		<div class="left"></div>
		<div class="right"></div>
	</body>
</html>
